In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 106, No. 13 ( 2009-03-31), p. 5246-5251
Abstract:
Flowering plants often prevent selfing through mechanisms of self-incompatibility (S.I.). The loss of S.I. has occurred many times independently, because it provides short-term advantages in situations where pollinators or mates are rare. The genus Capsella , which is closely related to Arabidopsis , contains a pair of closely related diploid species, the self-incompatible Capsella grandiflora and the self-compatible Capsella rubella . To elucidate the transition to selfing and its relationship to speciation of C. rubella , we have made use of comparative sequence information. Our analyses indicate that C. rubella separated from C. grandiflora recently (≈30,000–50,000 years ago) and that breakdown of S.I. occurred at approximately the same time. Contrasting the nucleotide diversity patterns of the 2 species, we found that C. rubella has only 1 or 2 alleles at most loci, suggesting that it originated through an extreme population bottleneck. Our data are consistent with diploid speciation by a single, selfing individual, most likely living in Greece. The new species subsequently colonized the Mediterranean by Northern and Southern routes, at a time that also saw the spread of agriculture. The presence of phenotypic diversity within modern C. rubella suggests that this species will be an interesting model to understand divergence and adaptation, starting from very limited standing genetic variation.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.0808012106
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2009
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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